Mechanical ciphering unit



Oct. 17, 195 L.. M. PoTTs 2,525,941

MECHANICAL CIPHERING UNIT Original Filed OCT.. 10, 1946 2 Sheets-Sheet 1Louis M. PoTTs, osceAsEn MARTHA w. c. PoTTs, execumx ATTORNEY Ont. 17,1950 L. M. PoTTs 2,525,941

MECHANICAL GIPHERING UNIT Original Filed Oct. l0, 1946 2 Sheets-Sheet 2FIG. 3 38 46 INVENTOR LOUIS M. POTTS, DECEASED MARTHA W. C.POTTS,EXECUTRIX ATTORNEY Patented Oct. i7, 1950 UNITED STATES PATENT GFFICEMECHANICAL CIPHERING UNIT Original application October 10, 1946, SerialNo.

Divided and this application Septembei' 27, 1947, Serial No. 776,526

Claims. l

This invention relates to secret printing telegraph apparatus andparticularly to mechanical ciphering units for enciphering anddeciphering telegraph messages.

This application is a division of copending application Serial No.762,429, filed October 10, 1946, matured into Patent No. 2,522,461.

The primary object of the invention is the provision of mechanicalciphering units for secreiI telegraph message communication.

Another object of the invention is to provide a mechanical cipheringunit including a mechanical chain linkage system in which variable pathsoi movement through the linkage are afforded for ciphering operations.

An additional object of the invention is the incorporation of amechanical ciphering chain system in a type Wheel printer.

A feature of the invention is to provide a ciphering type wheel printerwhich is all mechanical in operation and requires no motor, all powerbeing furnished from the keyboard,

In general, it is proposed to provide, in combination with a, ve unitcode selector which includes ve mechanical selectable elementspositionable to two different positions, a variable mechanical chain oreach selectable element. The positions of certain component parts of thechains are varied so that motion transmitted through the individualchains follows a variable path which ultimately determines the positionsoccupied by the selectable elements. To achieve such a result eachmechanical chain includes a plurality of pairs of slides which cooperatewith a plurality of pairs of ciphering levers Whose positions aredetermined by the setting of cam pairs of ciphering code drums which maybe stepped to a number of different positions. The code drum cams arecut so that the high parts of one cam are opposite the lovi7 parts ornotches of the companion member of the same pair of cams. This insuresthat the ciphering levers oi any pair will always be oppositelypositioned for operation to provide a continuous path of movementthrough the mechanical chains as will be more fully described later inthe specification.

One embodiment of the invention utilizes mechanical ciphering chains inconnection with a keyboard operated type wheel printer. The stoppingposition o the type wheel is determined by the selection of a stop pin,by means of a five unit code disc selector similar to the selectordisclosed in the Morton et al. Patent N o. 1,821,110. The positioning oithe code discs is determined by the operation of the mechanicalciphering chains, there being one chain for each element of the code. Inthis instance, an enciphered message can be typed on a tape and thensent by telegraph, courier, or other means to a predetermineddestination. An attendant at this destination by employing an identicaltype wheel printer may retype the received message which will then bedeciphered and printed in plain English. lt is, of course, assumed thatboth type wheel printers would be provided with identically cut key codedrums which will occupy the same relative positions during theenciphering and deciphering operation. An additional advantage oi thetype Wheel printer herein disclosed is that its operation is allmechanically controlled from the keyboard and requires no motor.

A better Iunderstanding of the invention may be had by reference to thedetailed description which follows when read with the accompanyingdrawings wherein:

Fig. 1 is a fragmentary iront elevational view particularly illustratingthe functional operations of the type Wheel printer;

Fig. 2 is a fragmentary front elevational View particularly illustratingthe operation of the selector mechanism of the type wheel printer;

Fig. 3 is an end view of the apparatus taken on the line 3--3 of Fig. 1;

Fig. 4 is an end View of the apparatus taken on the line 4 4 of Fig. l

Fig. 5 is a partial iront view of the apparatus showing particularly thelocking plate for the ciphering code drums;

Fig. `6 is an enlarged detailed perspective View of the mechanism foroperating the type wheel; and

Fig. 7 is an enlarged detail View oi a key slide blank.

Referring now to Figs. 1 to 7, inclusive, the embodiment of theinvention which is devoted to the type Wheel printer will now bedescribed. Referring to the parts by reference numerals, 3l representsthe base of the apparatus upon which is supported in any suitable mannera housing d2 composed of front and rear Walls 33 and 3d, respectively,end Walls 36 and 3l', and a top portion 38. Within the housing 32 aremounted a iront supporting member 39, an intermediate supporting memberlll secured to member 39 by means of bolts 25, and a rear supportingmember 42 integrally formed as part of the front supporting member 39 ina slotted guide i3 (Fig. 5). Similarly the rear supporting member l2 isprovided With a slotted guide, not shown, and belby associated springs4E.

tween it and the slotted guide 43 are mounted for slidable verticalmovement a series of key slides 44 normally urged to an upward positionAll the key slides 44 may be cut from the same blank as shown in Fig. 7by cutting off the undesired upward projections 4l' according to the rowof keyboard 4B in which it is desired to place the particular key slide.For example, if it were desired to make a particular key slide 44operable from the front row of keyboard 48 the middle and rear upwardprojections 41 would be cut off at 49. The key slides 44 also include acentrally located and downwardly depending portion 5I, designed to movein a lower guideway 52 which is suitably attached to the intermediatesupporting member 4I, while the middle upwardly extending projection 49is designed to ride in the upper guideway 5E) also mounted on member 4I.Keyboard 48 is provided with the usual space bar 53 Vpivoteol on eachside at 54 and normally urged in an upward direction by springs, notshown.

Mounted below the key slides 44 for horizontal slidable movement on rods56 and 5l are five pairs of permutation bars 58F, 555B. Each pair ofpermutation bars is composed of a front bar 58F and av rear bar SSR, thefront bars EBF being normally urged to the right as viewed in Fig. 2 bymeans of springs 59?, while the rear bars 58B are similarly urged to theright by springsvQR. The permutation bars EF, 58B. are respectivelyprovided with upwardly extending beveled cam projections GIF and GIRdesigned to be engaged by the lower edges of key slides 44 and are soarranged that for any given pair of bars 58F and 58Hl only one of thepair will move to the left when a key slide 44 is depressed. In otherwords, Where there is a projection @IF on a bar SEF there will be noprojection 6 IR at a similar point on bar 58B, of the same pair and viceversa.

It will be understood that although the operation of only one mechanicalchain will now be described there will be a similar chain for eachelement of the five unit code. Each of the permutation bars 58E, 53F isprovided near` its left end (as viewed in Fig. 2) with a notch 52, inwhich the upper arms GSF, SSR of a pair of operating levers MF, 64B,pivoted at 63 are nested. Operating lever tllF is designed to engage atits lower end a rearwardly extending lug F of slide 68F while operatinglever 64B, is designed to engage at its lower end a irontwardlyextending lug 61B, of slide R. Pivotally mounted in socket G9 of slide68F is a ciphering lever 'HF which is urged in aA counterclockwise orupward direction by means of its associated spring 12F. Ciphering leverlIR, is similarly mounted on the slide EiBR.

The positions of the pairs of ciphering levers I IF, 'I IR, aredetermined by the positions of associated pairs of sensing levers 13E,'I3Rwhich are pivoted at 'I4 and which by means of projections sense theperiphery of associated cam pairs TIF, TIR of code drums 60. Cam pairsTEF, I1-R are so notched that the 'high parts of cam HF of one pair aredirectly opposite the low parts or notches of the other cam 'VIR of thesame pair. The periphery of the cam pairs TIF, 'VFR may be cut in afortuitous manner. The just described cutting of the cam pairs insuresthat ciphering levers "HF, 'IIR of any pair of ciphering levers willalways be oppositely positioned. The free end of ciphering lever 'IIF or'IIR is designed to engage either the rearwardly extending lug TSF ofslide 'IF or the frontwardly extending lug 'I8R of slide TSR, dependingupon the notching of the cam pairs TIF, TER. Thus if ciphering levers'HF is down, as shown in Fig. 2, it will be in a position to engage alug 'ISF of slide TIS F. At this time ciphering lever 'IIR will be up orin a position to engage a lug lSR, of slide HSR.

The second code drum 'it is composed of cam pairs SIF, SER which bymeans of sensing levers 82F, 82B, control the positions of cipheringlevers BSF, 83B, respectively mounted for pivotal movement on slidesiSF, MR. Likewise, a third code drum Bil composed of cam pairs Sill-e,84B. by means of sensing levers SBF, 8d3, control the positions ofciphering leversv BTIF, SlR pivotally carried by their respective slidesSBF, 88B.. The free ends of ciphering-levers SBF, SSR may engage eitherthe rearwardly extending lug SQF of slide 88F or the frontwardlyextending lug 89B. of slide SSR. The free end of ciphering levers i'ilF,NR may engage either the rearwardly extending lug SIF of marking slide92M- or the frontwardly extending lug SIR of spacing slide $25. Markingslide M is designed to engage arm 93 of transfer' lever S4 pivoted at96, while spacing slide 92S is designed to engage arm 91 of transferlever 94. Transfer lever Q4 includes a rounded third arm Q8, which isnested in notchY SQ of an individual selector disc Il ci a five unitdisc selector I2. Discs IUI are freely mounted on shaft H33. Movement ofa marking slide 62M will, therefore, move an individual selector discIUI to a marking position and movement of a spacing slide 92S will movean individual selector disc I'I to its spacing position.

At right angles to and equally placed along the circumference of theselector disc lill and guided in guide plate I U4 (Fig. '3) are theusual stop pins IGS. rFhis type of five unit selector is well known inthe art and is fully described in the patent of Morton et al previouslyreferred to above. When the V-shaped slots IB'I of selector discs Il!!adjacent a particular stop pin |06 are in alignment, this pin will pivotinwardly due to the force exerted by garter spring |58 and assume aposition to stop movement of the type wheel stop arm led as will laterappear.

It can now be readily seen that when a key slide 44 is depressed one ofthe operating levers 64F, 54B, of each pair'will pivot at i in acounterclockwise direction and at its lower end push against one of theslides 68E', GSR moving it to the right. The positions of ciperinglevers TIF, 'HR will determine which of the slides TSF, 'ISR will beoperated, the positions of ciphering levers 83E', 83H will determinewhich of the slides 88F, SSR will be operated, and the positions ofciphering levers E'IF, STR, will determine whether a marking slide 92Mor a spacing slide 92S will be operated to position the individualselector discs II accordingly. Since the code drums 69, i0, Il!) arestepped to different positions as will later be described it is obviousthat the path of movement afforded for each mechanical chain will varywith the setting or" the code drums.

Positioned below all the key slides 44 for engagement by any one ofthem, after selected permutation bars 58 have been moved to the left aspreviously explained, is a universal bar III (Fig. l). The universal barIII is attached to end pieces ile which are welded to the key slides 44located at either end of the series of key slides. The key slides 44which support the universal bar Il I will have all three upwardprojections 47 cut therefrom at lig (Fig. 7) since in this case suchprojections are unnecessary. The universal bar II I is normally held inan upward position by springs 46 which are provided on all key slides44.

As the universal bar III moves downward when engaged by a particular keyslide 44 it strikes the laterally extending arm of a bell crank ||2which is pivoted at IIS. This causes the engagement of the upwardlyextending arm of bell crank i2 with a bent over flange I I4 of m-ainoperating slide I I6, causing the slide H6 to move to the right asViewed in Fig. l against the tension of a relatively strong spring ||1.The slide ||6 is mounted for horizontal movement by means of pin andslot connections |65, ||5.

The stepping of the code drums 66, 10, and 86 through actuation of themain operating slide ||6 will now be explained. It should be mentionedthat it is proposed that each code drum may be stepped to twenty-sixdiierent positions. The rst code drum 66 is carried by sleeve 66 whichis rotatably supported on fixed shaft ||6 suitably attached to the rearsupporting member 42. Integral with sleeve |96 is a raised annular disc|64 in which are seated dowel pins |56 which extend through flange |55of a second sleeve |56 mounted for rotation on fixed shaft I I8, throughratchet H9, through disc |23 and spacer |65. Thus when ratchet i i6 isrotated cam pairs 11F, 11R of code drum 66 will be rotated therewith.The dowel pins |56 are removable and provide means whereby adjustment ofthe cam pairs may be made. It is to be understood that code drums 16 and66 will be respectively mounted in a similar manner on fixed shafts A|29and Pawl |26 is urged into engagement with the teeth of ratchet SIS bymeans of a spring |22. Mounted adjacent to ratchet ||9 for movementtherewith is the disc |23 having a deep notch |24. As ratchet H9 isstepped by pawl |2I due to the reciprocation of slide |56 a positionwill be reached whereat lug |26 formed as an integral part of a steppingpawl |21 pivoted at |26 will enter the notch |24 of disc |23 allowingthis pawl to step ratchet |23, thereby causing movement of sleeve |66and the consequent stepping of five pairs of cams 3 |l1, SIR comprisingcode drum Secured on a sleeve |66 rotatable on fixed shaft |26 is a diseI3! having a notch |32 which at one position in its rotation will beengaged by a lug |33 integral with stepping pawl |34 pivoted at |36 tothe main operating slide H6. Pawl |34 is urged into engagement with theteeth ci ratchet |33' by means of a spring |36. Ratchet |31 is securedon a sleeve |66 rotatably mounted on fixed shaft |39 and drives the fivepairs of cams 84E', 84B. The code drums may thus provide 17,576 (26 tothe third power) key ciphering selections without repetition since thereare 26 teeth in each of the ratchets H6, |28, and i3?. Increasing thenumber of code drums and thus lengthening the chains would, of course,increase the number of key selections.

The operation of type wheel stop arm |69 will now be explained. The mainoperating slide i6 has secured thereto an adjustable plate |4| which isadjustable by means of screws |42. Formed as part of adjustable plate|4I is a rack portion 443 (Fig. 6) which is in engagement with a pinion44 loosely mounted by means of a hub |46 to a shaft |46 suitablyjournaled on the supporting member 4Z by bushing |41. Secured to shaft|48 is a gear segment |45 which is urged in a counterclockwise directionas viewed in Fig. 6 by means of a spring |5| which is weaker than thespring l l1 that normally holds slide H6 to the right as viewed in thesame gure. Carried by shaft |48 is a lug |52 which engages in a notch|53 on hub |46 and due to the force exerted by spring |5| on shaft |48,lug |52 normally tends to follow the movement of pinion |44 by itsengagement in notch |53.

Gear segment |46 engages at its toothed portion |54 a pinion |56attached to shaft |51 which is mounted in bushings |45. Shaft |51carries type wheel |58 and stop arm |66, each being connected to theshaft |51 by means of sleeve |59. It should be noted that normally theforce exerted by spring ||1 on operating slide ||6 through rack |43,pinion |44, gear segment |49, and pinion |56 holds stop yarm |09 againsta xed stop member |62. This gearing arrangement just described whichdrives stop arm |69 is of a very high ratio so that a small movement ofslide i I6 enables a relatively greater movement of the stop arm whichis capable of movement until blocked by any selected pin |66 as will nowbe described. By means of adjustable plate |4| the operative position ofrack |43 with respect to pinion |44 may be varied.

The play allowed between lug |52 of shaft |48 and notch |53 of hub |46insures that the stop arm |65 may move to any of its positions accordingto the selection of a, particular stop pin |66 and still allow furthermovement of the main operating slide ||6 to complete other functions.Thus when a. key slide 44 is depressed and slide |6Vmoves to the left asviewed in Fig 6, rack |43 will rotate pinion |44 counterclockwisecausing notch |53 to tend to move away from lug |52. However, the forceof spring |5| acting on gear segment |49 attached to shaft |48 enablesthe lug |52 to follow notch |53 until stop arm |69 encounters theselected stop pin I6. It should be remembered that universal bar is notoperated until a selection is made as has already been pointed out, andtherefore, a stop pin |66 will be selected prior to movement of stop arm|66. When the stop pin |56 is encountered by stop arm |65 furthermovement of slide I6 to the left is permitted due to the play betweenlug |52 and notch |53. The amount of additional movement of slide ||6after a pin |66 is encoun tered is determined, of course, by which pinis selected. If the nearest pin to the stop arm |69 is selected therewill be a maximum of further movement of slide I I6, Whereas if thefurtherest pin |66 is selected there will be a minimum ci additionalmovement.

A description of the printing and tape feeding tape operations will nowbe undertaken. Suitably pivoted at |63 to a xed part of the apparatus isa bell crank I 64 having an upstanding arm |65, the upper end of whichrests between pins |66 attached to the main operating slide H6. To thelaterally extending arm |61 of bell crank |64 is pivoted at |68 a pawl|69. Also carried by arm |61 of bell crank |64 is a tape stepping pawl|1I which is pivoted at |12. Pawls |69 and |1| are urged in oppositedirections about their pivots by means of a connecting spring |13. Pawl69 is provided for stepping ratchet |14 carried on the shaft |16.Attached to a suitably mounted rock shaft |11 is a bell crank |18 havingan arm |18 which is urged into engagement with ratchet |14 by means ofthe spring |8I. Also xed to rock shaft |11 for movement therewith is theprint hammer lever |82 carrying at its free extremity the usual printingelement |63. Thus, as the main operating slide ||6 moves to the right asviewed in Fig. l pins |66 carried thereby will cause a clockwise pivotalmovement of bell crank |64 which thereby operates pawl |69 to step theratchet |14. At this time arm |19 of the bell crank |18 is cammedoutwardly tensioning the spring |8|. As bell crank |64 reaches itsextreme clockwise position, arm |19 now moves over a. tooth of theratchet |14 enabling spring |8| to move the print hammer lever |82 in acounterclockwise direction causing a sharp operation of the printingelement |83. Immediately thereafter pawl |1| which has moved away fromthe tape feeding ratchet |10 engages the neXt tooth of ratchet |10 tothereby step the tape forward one position for the next operation.Ratchet |10 is secured to a shaft |80 which at its other end carries thetape feed wheel |84.

For setting the code drums 90, 10, and 89 to prearranged positions eachof the shafts H8, |29, and |39 are provided with dials |86. To preventtampering with the code drums after they have been set, plate |81 (Fig.5) is mounted for vertical movement on pins |88. This is accomplished bymeans of a standard cylinder lock |89 (Fig. 5) which, when operated by akey, moves shaft |9| and eccentric |92 welded thereto in acounterclockwise direction. This lifts the plate |81 upwardly by meansof slot |95 engaging pin |90 carried by plate |81, so that it becomeslocked in the grooves |93 of discs |94. Clearance, however, is providedso that discs |94 are free to rotate. Discs 94 are formed as integralparts of sleeves |96 which are rotatable on the shafts |18, |29, and |31and carry respectively code drums 60, 10, and 88. Plate |81 includesbent over and rearwardly extending projections |91 which overliethesensing levers 13, 82, and 86 and will disengage them from theirrespective code drum's 11,

8|, and 84 when the plate |81 is moved downward. This permits freeaccess to and withdrawal of the code drums whenever necessary foradjustment or other purposes.

At the front of the housing 32 is mounted a compartment |98 (Figs. 3 and4) which underlies the type wheel |58 and houses a tape feed wheel |84and may include a tape guiding means (not 1shown) for tape |99. Means,not shown, will also be provided for feeding inking ribbon |85 in anyconventional manner.

A brief rsum of the operation of the type wheel printer will now begiven. lKey slide 44 is depressed which through the ve mechanical chainsprovided inthe present invention results in the setting of the veindividual selector discs i! and the selection of a particular stop pin|08. The key slide 44 now engages universal bar thereby operating bellcrank ||2 and moving the main operating slide I6 to the right as viewedin Fig. l. This operates gear segment |49 causing rotation of stop arm|09 until it is stopped by a selected stop pin |06. Main operating slidecontinues to move to the right, tensioning spring |8| of bell crank |18and causing operation of print hammer lever |82 with a snapping action.As the main operating slide H5 returns to the left, pawl |1| operatestape feeding ratchet |10 to step tape |99 to its next position. At thesame time pawl V|59 assumes a position to engage the next tooth ofratchet |14.

Return movement ofl main operating slide 1| |6 to the left causes pawl2| to step ratchet ||9 to its next position, and when the notch |24 ofdisc |23 is presented to 'lug |28.of pawl |21 this' latter pawl willstep ratchet |28 to its next position.r Also when notch |32 of disc 3|is presented to lug |33 of pawl |34 this pawl will step ratchet It isunderstood that various changes andv modifications may be made in thepresent invention without departing from the spirit and scope thereof.

What is claimed is:

l. In a type wheel printer, atype wheel, a

. plurality of selectable elements for determining operating saidprinting means after said type the stop position of said type wheel, amechanical chain for each of said selectable elements including a seriesof pairs of movable members, mechanical means for variably selectingeither one of each pair of movable members for movement, means foroperating each of said chains to select said selectable elements, meansfor causing said type wheel to move to its selected stop position,printing means in operative relation with said type wheel, and means foroperating said printing means after said type wheel has been positioned.

2. In a type wheel printer, a type wheel, a plurality ofselectableelements for determining the stop position of said typewheel,a mechanical chain for each of said selectable elements vhaving at leasttwo parallelly arranged linkage systems each including variablypositionable elements, means to Vary the position of said variablypositionable elements, means to operate each of said chains inaccordance with the operation of said position varying means to therebydetermine the selection of said selectable elements, meansv for causingsaid type wheel to move to its selected stop position, printing means inoperative relation with said type wheel, and means for wheel has beenpositioned.

3. In a type wheel printer, a type wheel, a plurality of selectableelements for determining the stop position of said type wheel, amechanical chain for each of said selectable elements having at leasttwo parallelly arranged linkage sys-` tems each including variablypositionable elements, key operated means for varying the position ofsaid variably positionable elements, means to operate each of saidchains to provide a continuous path of movement through parts of atleast two linkage systems of each of said Chains or completely throughone linkage system dependent on the operation of said key operated meansto thereby control the selection of said selectable elements, means forcausing said type wheel to move to its selected stop position, printingmeans in operative relation with said type wheel, and means foroperating said printing means after said type wheel has been positioned.

4. In a printer, a plurality of character selecting elements, amechanical chain for each of said elements having at least twoparallelly arranged linkage systems each including variably positionableelements, means to vary the position of said variably positionableelements, means to operate each of said chains in accordance with theoperation of said position Varying means to thereby determine theoperation of said character selecting elements, and printing means forprinting a character selected by said character selecting elements.

5. In a printer, a plurality of character selecting elements, amechanical chain for each of said elements having at least twoparallelly arranged linkage systems each including variably positionableelements, key operated means for varying the position of said variablypositionable elements, means to operate each of said chains to provide acontinuous path of movement through parts of at least two linkagesystems of each of said chains or completely through one linkage systemdependent on the operation of said key operated means to thereby controlthe selection of said character selecting elements, and printing meansfor printing a character selected by said character selecting elements.

MARTHA W. C. POTTS, Eecutrirc Under the Last Will and Testament of LouisM. Potts, Deceased.

REFERENCES CITED FOREIGN PATENTS Country Date Italy of 1934 Number

